package com.zzw.hj10;

import java.util.Scanner;

/**
 * @Project: hw_java
 * @Description: 字符个数统计
 * @Author: zzw
 */

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        char[] charArray = str.toCharArray();
        int[] b = new int[128];
        int count = 0;
        for (int i : charArray) {
            b[i]++;
        }
        for (int i = 0; i < 128; i++) {
            if (b[i] > 0) {
                count++;
            }
        }
        System.out.println(count);
    }
}